JPH06130481A - Display device - Google Patents

Abstract

PURPOSE:To make observation with high lightness and good perceptivity by providing two optical paths for illuminating two adjoining display parts, and allowing one of them to lead the light flux from a light source to the projector lens side via reflexion. CONSTITUTION:An optical member 32 consisting of a prism member in a specified shape is installed on an optical path leading from a light source 103 to a projector lens 13'. The light flux from LEDs 103a-103e for displaying is deflected to a certain direction by the optical member 32 and passed through the projector lens 13' to selectively illuminate display parts 21a-21e of the distance measuring field, etc., on the plane of a focusing glass 10. Therein the light fluxes from the LEDs 103b, 103d are cast on the optical member 32 from surfaces 32b, 32d. They are total reflected by surfaces 32f, 32g, substituted with light fluxes of LEDs 103a, 103e, emitted from a surface 32h, and cast onto the display parts 21b, 21d. Thereby the positions of LEDs 103a-103e can be arranged apart from one another while the illumination scope on the focusing glass 10 is left fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device in a finder suitable for a photographic camera, a video camera or the like, and more particularly to a display body for displaying information such as a distance measuring range and a photometric range at an arbitrary position within the finder visual field. The present invention relates to a display device in which an object image formed by a photographing lens is observed together with the display body.

[0002]

2. Description of the Related Art Conventionally, in a single-lens reflex camera or the like such as a photographic camera or a video camera, a focusing plate-like object image formed by a photographing lens is used together with or on the focusing plate or optically equivalent to the focusing plate. 2. Description of the Related Art A display device is used in which a display body such as a range-finding range or a photometric range arranged at a position is simultaneously observed through a finder system.

FIGS. 5 to 9 are schematic views of a main part of a single-lens reflex autofocus camera having a conventional display device. 5 and 6 are a top view and a sectional view of the single-lens reflex autofocus camera.

In the figure, 1 is a camera body, 2 is an objective lens 3.
A lens barrel for holding 4 is a release button, 5 is a setting dial that can be operated with the right index finger, DSP is a liquid crystal display for externally displaying the currently selected distance measuring field, 7
Is a mode selection member for selecting either the shutter speed priority mode or the aperture value priority mode, and 8 is a distance measuring field selection mode button. Further, 9 is a movable half mirror, 10 is a focus glass having a Fresnel lens 10f on the light incident surface, and a matte surface 10g on the light emitting surface, and 11 is a penta prism.
Reference numeral 12 is an eyepiece lens. Each of these elements 10, 11,
Reference numeral 12 constitutes a part of the finder system.

Reference numeral 13 is a projection lens having two reflections for displaying a distance measuring field for superimposing, and reference numeral 13a is a Fresnel lens provided in a part of the projection lens 13. 10
3 is a display LED, and 114 is a package that holds the LED 103. The light emitted from the LED 103, after passing through the mask 30, is guided onto the focus glass 10 through the light projecting lens 13 and the main mirror 9, and illuminates a display prism on the focus glass 10 described later.

Reference numeral 16 denotes a known focus detecting device, which is provided at a position corresponding to a distance measuring visual field display for superimpose described later.
It has individual distance measuring fields. The object light transmitted through the movable half mirror 9 is guided to the focus detection device 16 via a sub mirror 15 arranged behind. Reference numeral 6 denotes an LED that emits infrared light, and constitutes an auxiliary light projection device together with the auxiliary light projection lens 18. Reference numeral 17 is a package that holds the LED 6.

The display of the distance measuring visual field selected by the photographer is displayed in the viewfinder visual field at the same time as the display unit outside the camera.

FIG. 7 is an explanatory view of the distance measuring field displayed in the finder field, and 20 in the figure is the finder field.
Reference numerals 21a to 21e are display units showing a distance measuring field for superimposing. As will be described later, the illumination light from the LED selectively changes the color of one of the display units 21a to 21e.

FIGS. 8 to 9 are explanatory views for more specifically explaining the display unit showing the distance measuring field for superimposing described above.

FIG. 8 is a perspective view of the main part of the display section. 114a to 114e in FIG. 8 are the LED 1 shown in FIG.
14a to 14c are packages for displaying LEDs (not shown) including 14c, each showing a distance measuring field.
21e. The focus glass 10 is shown in FIG.
As shown in detail in (B), the display portions 10a to 10e (display portion 21a) including a large number of prisms on the matt surface 10g.
(Corresponding to 21e) is formed.

When the display LEDs held in the packages 114a to 114e of FIG. 8 are caused to emit light, the luminous flux passes through the light projecting lens 13 as shown in FIG. 6 and is reflected by the movable half mirror 9 to be brought into focus glass. Display on 10 (10a
To 10e). At this time, due to the action of the Fresnel lens 13a of the light projecting lens 13, the LED 10 held by one LED (for example, the package 114c)
It is configured such that one display element (for example, 10c) of the display unit is illuminated by the light emission of 3.

FIG. 9B is a detailed view of the area A indicated by the dotted line in FIG. This figure shows packages 114a-11.
FIG. 9B shows the optical path of the illumination light from the LED held by 4e. In FIG. 9B, 22 and 23 are the illumination light from the LED 103, which is obliquely incident on the focus glass 10 from the movable half mirror 9. Among them, the light ray 22 is refracted by the prism of the display unit 10c and is deflected upward, while the light ray 23 is emitted from the matte surface 10g and diffused around the upper side of the slope.

Therefore, when observing the display portion 10c through the pentaprism 11 and the eyepiece lens 12, only the prism portion appears to change to the emission color of the LED 103. L held in the packages 114a to 114e
By selectively illuminating the EDs 103a to 103e (however, only the LED 103c is shown in FIG. 6), the currently selected distance measuring field is displayed in the viewfinder field 20 in a superimposed manner.

In addition to this, as a display device used for a camera or the like, it is arranged between a pair of polarizing plates arranged so that their polarization directions are orthogonal to each other, and the opposing substrate surfaces of a pair of transparent substrates are subjected to an orientation treatment orthogonal to each other. Then, a method using a TN type liquid crystal display element in which liquid crystal is sealed, a method using a prism display element in which a large number of prisms are formed on a transparent substrate and obliquely illuminated to perform color change display, and a laser light A method using a hologram display element created by utilizing interference is known.

[0015]

Since the display device in the finder shown in FIGS. 7 and 8 illuminates the display section showing the distance measuring fields arranged on the focus glass 10, one of these is used.
It has an LED corresponding to one. This LED is behind the mask opening 30 arranged at the position where the display unit is back projected by the light projecting lens 13, and is arranged in parallel for the number of distance measuring fields.

At this time, especially in a single-lens reflex camera or the like, the mask aperture 3 formed by the light projecting lens 13 is required due to the demand for size reduction.
The projection magnification of 0 is a magnified projection of about 1.5 to 5 times, and if the distance measurement visual field interval is 3 mm, the interval of the mask openings is about 2 mm to 0.6 mm. Therefore, LE
The interval of D is similar to this.

Generally, the LED is enclosed in a transparent resin package as shown in FIG. 8, and when it is desired to allow the emitted light to efficiently enter the light projecting lens 13, a tube having a spherical end is provided. LE in the shape of a package
It is preferable to set the depth of D to a position two to three times the radius from the tip.

Further, the larger the radius of the spherical portion at the tip, the larger the amount of light. This is because a larger package can accommodate a larger LED chip, a light reflecting surface that is a part of a lead can be provided in the back portion of the LED chip inside the package, and the focal length of the spherical portion can be set to the LED. This is because it can be set so that the image of the chip does not become too large.

By the way, the maximum amount of light currently available is an LED.
In order to obtain a sufficient amount of light as a light source for a display device in a viewfinder such as a single-lens reflex camera that is used outdoors during the daytime, using a projection magnification of 2.5 times It is necessary to store it in a package of about 3 mm. Compared with this value, the above-mentioned LED spacing 2
mm-0.6 mm is extremely small, and as a result, there is a problem in that the visibility of the display unit in the bright outdoors is considerably reduced.

A first object of the present invention is to provide an appropriately set optical means between a light source for illuminating a plurality of display portions and a light projecting lens, and utilize the optical means to efficiently operate the plurality of display portions. An object of the present invention is to provide a display device that is bright and can be viewed with good visibility by illuminating well.

Among the above-mentioned display devices, the method of using the TN type liquid crystal display element is widely used because it has a simple structure and is easy to drive, but two polarizing plates are used. Since the light flux is transmitted and blocked, the transmittance at the time of light transmission cannot be increased in principle, and a bright viewfinder optical system cannot be obtained.

Further, since the finder image is dark and the display is made by blocking the light flux, there is a problem that it is very difficult to see in a dark place.

Next, the method using the prism display element is an active type display, in which a display pattern visually recognized as black even when the illumination light is not illuminated looks like a light source color when illuminated with the illumination light. And is advantageous in terms of transmittance. Further, since it is an active display using illumination light, there is an advantage that it can be surely viewed even in a dark place.

However, in any case, it is difficult to make the display pattern in the non-display state, the viewfinder field becomes complicated, and even meaningless information is displayed depending on the state of the camera. is there.

On the other hand, the method using the hologram display element has good visibility in a dark place because it is an active display like the method using the prism display element, but it is difficult to obtain a display element having high diffraction efficiency. The characteristic is that it is almost invisible when no illumination light is applied. This poses a problem that it is difficult for the photographer to perform an operation when selecting one of them, for example, while looking at the display element showing the distance measuring field.

A second object of the present invention is to form a plurality of display sections by using a phase type diffraction grating, and appropriately set the configuration of an illuminating means for illuminating the plurality of display sections to form a finder image. 1 out of multiple displays while keeping bright
An object of the present invention is to provide a display device capable of observing well by selecting one of the display portions.

[0027]

According to another aspect of the present invention, there is provided a display device comprising: (1-a) a plurality of display portions having a light-deflecting property arranged in the vicinity of a planned image forming surface where an object image is formed by an objective lens. Of the plurality of display units is selectively illuminated with a light flux from the light source of the optical system through the optical member and the light projecting lens, and when the illuminated display unit and the object image are observed, the optical The member is characterized in that one of two optical paths for illuminating two adjacent display sections of the plurality of display sections guides the light flux from the light source to the light projecting lens side through reflection in one optical path. I am trying.

(1-b) A display section utilizing a phase type diffraction grating is provided in the vicinity of a planned image plane on which an object image is formed by the objective lens, and the display section is illuminated by a light beam from an illumination means having a light source. When the diffracted light generated by the illuminated diffraction grating of the display section is guided to the finder system and the display section and the object image are observed, the diffraction state of the diffraction grating is controlled by the control means, The first operation mode in which the light flux from the taking lens is not incident on the finder system and the light flux from the illumination means is incident on the finder system, and the light flux from the taking lens is incident on the finder system, and A second light flux from the illuminating means is non-incident on the finder system
The feature is that the operation mode is switched to.

In particular, the diffraction grating is a relief type diffraction grating provided between two substrates, and the control means changes the refractive index of the refractive index variable substance filled between the substrates, thereby performing the diffraction. The feature is that the diffraction state of the grating is controlled.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of a main part of a first embodiment when the present invention is applied to a single-lens reflex camera, FIG. 2 is a schematic view when an optical path of a part of FIG. 1 is developed, and FIGS. It is explanatory drawing of a part of FIG. 1 to 4, the same elements as those shown in FIGS. 5 to 9 are designated by the same reference numerals.

This embodiment is different from the conventional single-lens reflex camera of FIG. 6 in that the optical member 32 (FIG.
Is disposed between the light source 103 and the light projecting lens 13. A large difference is that the plurality of display units 21 for distance measuring fields on the surface of the focus glass 10 are selectively illuminated by the luminous flux from the LED 103, and other configurations are the same.

Next, the features of the present embodiment will be described with reference to FIG.
Although it partially overlaps with the explanation, it will be explained. The light flux from the LED 103 held in the package 14 (which has five packages 14a to 14e in this embodiment) is mask 31.
The light beam diameter is limited by, and after being deflected in a predetermined direction by the optical member 32, it is condensed by the light projecting lens 13, and the Fresnel lens 13a
The display unit 21 (21a to 21e) on the surface of the focus glass 10 as shown in FIG. 7 is selectively illuminated via the main mirror 9. Then, one of the distance measuring fields 21a to 21e on the surface of the focus glass 10 illuminated by the LED 103 is observed by the eyepiece 12 via the pentaprism 11.

Next, the optical function of the optical member 32 will be described with reference to FIG.

FIG. 2 shows the reflection inside the projection lens 13, the reflection inside the pentaprism 11 and the reflection at the main mirror 9 by expanding the optical path. 13 'is a state where the projection lens 13 is expanded, and 11' is a state where the pentaprism 11 is expanded. The light emitting surface 13'a of the light projecting lens 13 'is a Fresnel lens, and the light incident surface 13'b is a slight concave surface.

14a to 14e are LED packages,
As shown in FIG. 1, the display LED 103a is provided inside this.
It holds 103 to 103e (only 103c is shown). LE
The light flux emitted from the D package enters a mask 31 as shown in FIG. 3 arranged adjacent to the light flux. As shown in FIG. 3, the mask 31 has five LEDs 103a to 1a.
Five openings 31a to 31e corresponding to 03e are formed to regulate the illumination range on the focus glass 10.
The light flux narrowed down by the mask 31 then enters the optical member 32 including a prism shown in FIG.

The optical path here is divided into light sources (103a to 103).
e). First, the light flux emitted from the LED 103c and emitted from the package 14c is transmitted through the opening 31 of the mask 31.
After passing through c, the light enters the optical member 32 from the surface 32c. After that, it is emitted from the surface 32h and reaches the projection lens 13,
Display part 21c for the focus detection field in the center on the focus glass 10
Irradiated on.

Next, the luminous fluxes emitted from the LEDs 103a and 103e and emitted from the packages 14a and 14e are mask 31.
Through the openings 31a and 31e, and enters the optical member 32 through the surfaces 32a and 32e. After that, the light is emitted from the surface 32h, reaches the light projecting lens 13, and is irradiated on the outermost distance measuring field display portions 21a and 21e on the focus glass 10.

Finally, the LEDs 103b and 103d are emitted,
The light flux emitted from the packages 14b and 14d passes through the openings 31b and 31d of the mask 31, and the surfaces 32b and 32d.
Is incident on the optical member 32. Then, the surfaces 32f, 32
By performing total reflection at g, the LEDs 103a and 103e
The light beam is emitted from the surface 32h after being substantially interchanged with the light beam of, and reaches the light projecting lens 13. Therefore, on the focus glass 10, the display portions 21b and 21d for the distance measuring field are illuminated.

As described above, in the present embodiment, the optical function of the optical member 32 allows the light sources (103a to 103e) to be arranged apart from each other while the illumination range on the focus glass 10 is fixed. ing.

In FIG. 1, 1 is a camera body, and 2 is a lens barrel which holds an objective lens 3. Reference numeral 9 is a movable mirror, and focus glass 10 is a Fresnel lens 1 on the light incident surface.
0f, and a matt surface 10g on the light exit surface.

The focus detection device 16 is capable of measuring distances at a plurality of positions corresponding to the distance measuring fields 21a to 21e for superimposing shown in FIG. The object light transmitted through the movable half mirror 9 is guided to the focus detection device 16 via a sub mirror 15 arranged behind. Reference numeral 106 denotes an LED that emits infrared light, and constitutes an auxiliary light projecting device together with the auxiliary light projecting lens 18. Reference numeral 17 is a package that holds the LED 6.

In the present embodiment, as described above, by arranging the optical means 32 formed of a prism member having a predetermined shape in the optical path between the light source 103 and the light projecting lens 13, irradiation of a plurality of display portions is achieved. A large amount of light is provided so that a plurality of display units can be satisfactorily observed even in bright outdoors.

FIGS. 10 and 11 are schematic views of the essential parts of the second embodiment when the present invention is applied to a single-lens reflex camera. 12
Is a cross-sectional view of a main part of a single-lens reflex camera according to a second embodiment of the present invention, and FIG. 13 is a plan view of the main part of FIG. 14 to 26 are explanatory views of each element for explaining the second embodiment.

In the figure, 1 is a camera body, 2 is a lens barrel for holding a replaceable photographing lens (objective lens) 3, which is detachably attached to the camera body 1. These are a camera mount 1a and a lens mount. It is connected with 351a. In the camera body 1, 9 is a movable half mirror, which rotates about a rotation shaft 9a. An operation pin 9b faces the mirror driving cam 311.

Reference numeral 11 is a pentaprism, and 215 is an eyepiece lens. Reference numeral 306 is a light receiving element for photometry. Reference numeral 307 is a photometric calculation circuit, which is a film sensitivity information input circuit 308, a shutter control circuit 309, and a microcomputer 310.
Connected with. A focal plane shutter 334 and a mirror driving motor 312 are connected to a motor drive circuit 313. A film winding / rewinding motor 314 is a mirror driving motor 312.
Is connected to the motor drive circuit 315 in the same manner as. A distance measuring sensor 55 is connected to the distance measuring calculation circuit 317.

Reference numeral 214 is a photoelectric conversion element such as a CCD, which is connected to the line-of-sight detection circuit 330. Reference numeral 25 is a display element (display section) provided on the focus glass 10
03 and the like are connected to the display circuit 331. 318
Is a battery for operating the entire camera system, 319 is a main power switch, 320 is a DC / DC converter,
The battery 318 is connected to the microcomputer 310. Reference numeral 321 is a photometric distance measuring switch, and 322 is a release switch.

Incidentally, the switches 321 and 322 are generally two-stage stroke switches, and are constituted so that the switch 321 is turned on by the first stroke of the release button and the switch 322 is turned on by the second stroke. .
SWS is a setting dial, a mode selection member, which will be described later,
It is a switch connected to the distance measuring field fixing mode button.

Reference numerals 323a to 323e are contact pin groups on the camera body 1 side and are installed near the mount 1a. On the other hand, reference numerals 352a to 352e are contact pin groups on the side of the interchangeable lens body 2 and face the contact pin groups 323a to 323e on the camera 1 side.

On the side of the interchangeable lens 2, G1, G2, G
Reference numeral 3 is an optical lens which constitutes a photographing lens. 35
A lens driving motor 3 is used for focus adjustment and is connected to the lens driving circuit 354. By the rotation of the lens driving motor 353, the pulse number is input to the counter 362 via the ratchet 360.

A diaphragm drive circuit 361 is connected to the microcomputer 355 and to the pulse motor 356, and the motor 356 drives the diaphragm SP. Reference numeral 357 denotes a zoom drive motor used during zooming, which is connected to the zoom drive circuit 358.
Reference numerals 359a to 359e are encoders for transmitting the lens focal length to the microcomputer 355. 36
3 is a power zoom switch, 364 is a changeover switch for switching between AF priority and power zoom priority,
In the AF priority state, zoom drive during focus drive is prohibited, and conversely, in the power zoom priority state, focus drive during zoom drive is prohibited.

Reference numeral 4 is a release button for operating the switches 321, 322, 5 is a setting dial which can be operated by the index finger of the right hand, and DSP is a display circuit 33 together with a display element described later.
1, a liquid crystal display connected to 1, a mode selection member 7 for selecting one of the shutter speed priority mode and the aperture value priority mode, and 8 a distance measuring field fixing mode button. Input with the setting dial 5,
Is set.

Further, 10 is a Fresnel lens 1 on the light incident surface.
0f, a focus glass having a matt surface 10g on the light exit surface, 25 a display element (display unit) having a phase type diffraction grating, and 209 an optical splitter that reflects infrared light and transmits visible light. . Each of the elements 10, 11, 12, 215 constitutes a finder system.

Reference numeral 13 is a projection lens for active superimposing display, 13a is a Fresnel lens provided in a part of the projection lens 13, and 13b and 13c are projection lenses 13.
It is a total reflection surface of. Reference numeral 103 (103c) is a display LED, and 14 (14c) is a package holding the LED 103. The light emitted from the LED 103 is transmitted through the projection lens 13 and the movable half mirror 9 to the piston glass 1
It is guided in the direction of 0 and illuminates the central portion of the display element 25 provided on the surface. Further, five LEDs 103a to 103e are arranged in a line in the direction perpendicular to the paper surface of the LED 103,
It is configured to illuminate the peripheral portion of the display element 25.

Reference numeral 16 is a focus detecting device, which is a distance measuring sensor 55.
And a distance measurement calculation circuit 317, etc., and provided at a position corresponding to a distance measurement field frame by superimpose display described later.
Focus detection is performed in each distance measuring field. The sub mirror 1 in which the object light transmitted through the movable half mirror 9 is arranged behind
It is led to this focus detection device 16 via 5. Also,
Reference numeral 106 denotes an infrared LED, which constitutes a distance measuring auxiliary light device together with the auxiliary light projecting lens 18 and is a part of the focus detection device 16.

Here, 17 is a package for holding the LED 106. 211 is a condenser lens, 212 is an infrared half mirror having a reflectance of 50% with respect to infrared light,
Reference numeral 213 is an infrared LED, 214 is a photoelectric conversion element such as a CCD, and each of these elements 211 to 214 constitutes a part of the visual line detection device.

Next, the focus detection device 16 according to this embodiment will be described. 19 to 21 are explanatory diagrams related to the focus detection device. A so-called phase difference detection method is used as the distance measuring principle of the focus detection apparatus of this embodiment.

FIG. 19 is a perspective view of a main part of the focus detection device, FIG. 20 is a vertical cross-sectional view of FIG. 19, and FIG. 21 is a positional relationship between a pixel row of a photoelectric conversion element composed of a single chip of FIG. 19 and a light amount distribution. Are shown respectively.

In FIGS. 19 to 21, reference numeral 42 designates a porous field mask, which has five rectangular openings 42a to 42e arranged in parallel and having long sides in the lateral direction. For example, a planned image forming plane of the taking lens 2 in FIG. It is placed in the vicinity. Reference numeral 43 denotes a filter for blocking light having a wavelength longer than that of near-infrared light, and reference numeral 50 denotes a split field lens, which is arranged so as to be slightly displaced from the planned image forming surface of the photographing lens 3. As will be described later, the split field lens 50 includes three lens portions 50c, 50 having different optical functions.
d, 50e, and these parts are formed by changing one or both of the lens thickness and the radius of curvature of the lens surface. When the lens parts are formed separately, they may be made of materials having different refractive indexes.

Reference numerals 51 and 53 denote lenses, which form a re-imaging lens unit with a two-hole diaphragm 52 interposed therebetween. The two-image forming lens 53, in which the convex lens 51 and the two convex lenses 53a and 53b (see FIG. 19) are arranged and cemented, has a function of forming two secondary images of the object image formed by the taking lens 3. The above-mentioned two-hole diaphragm 52 is provided with vertically long elliptical openings 52a and 52b arranged in the horizontal direction in FIG.

Reference numeral 54 denotes a concave lens for correcting field curvature, which is arranged on a transparent plastic package 56 which houses the photoelectric conversion element 55 (FIG. 21). The split field lens 50, the convex lens 51 and the concave lens 54 of the re-imaging lens unit are shaped to be vertically long, but they are all spherical lens systems to be rotated.

42 of the perforated field mask 42 ...
The light flux that has passed through f passes through the lens portions 50c, 55d, and 50e of the split field lens 50 as shown in FIG. 20, and forms a secondary image of the object on the photoelectric conversion element 55, respectively.

FIG. 21 shows this state, which is 60c.
And 60d ... 60k and 60l are a set of pixel columns composed of a large number of pixels. .., 61l of openings 42b ..... 42f of the perforated field mask 42 are projected corresponding to these pixel rows, and a secondary image of the object is formed therein. At that time, the width of the openings of the porous field-of-view mask 42 and the light shields 42i ... 42l between the openings are set according to the width of the pixel rows and the pitch of the pixel rows on the photoelectric conversion element 55, and the predetermined openings are emitted. A part of the light flux is prevented from entering a pixel row other than the pixel row that corresponds to this opening on a one-to-one basis.

Further, the field mask image is composed of the diaphragm apertures 52a,
By the action of 52b and the lens portions 53a, 53b, two perforations are formed side by side in one opening of the perforated field mask 42, and two of the objects inside the two are formed in relation to the position of the object image with respect to the planned imaging plane. The next image moves in the directions A and B in accordance with the focus state of the taking lens 3.

Therefore, the set of each pixel row detects the relative interval of the light quantity distribution regarding the secondary image forming a pair based on the output of the photoelectric conversion element 55, so that the taking lens 3 at a plurality of distance measuring positions is detected. You can know the focus state of.

If the pixel array has a shape adapted to the distortion of the field mask image and the moving direction of the secondary image and the pixel array direction are completely aligned with each other, the distance measuring field on the planned image forming plane will be described. Is a straight line, which is convenient for forming a distance measuring field frame described later.

As described above, in the focus detection device of the phase difference detection system, it is necessary for focus detection to form a pair of subject images whose phase changes according to the image formation state of the taking lens 3. It is a condition. Therefore, even if a part of the light flux forming a pair of subject images is vignetted, the similarity between the two images is reduced and the result of focus detection becomes unreliable.

Next, the information of the taking lens 3 for determining whether or not focus detection is possible will be described.

FIG. 22 is an expanded view showing the relationship between the taking lens 2 and the distance measuring light beam. 70 is a shooting screen, 71
Is a distance measuring visual field located off the optical axis 72 of the taking lens. The distance measuring light flux entering the distance measuring visual field 71 is as shown in FIG.
It is determined by the two-hole aperture 52 and the split field lens 50 shown in FIG.
The image is back projected through two apertures.

By the way, the aperture of the photographing lens 3 which determines the photographing light flux differs not only for each interchangeable photographing lens, for each zoom position and each position of the distance ring, but also for the position within the photographing screen, The change is particularly large in the aperture opening state where the distance is performed. This means that the easiness of vignetting of the distance measuring light beam varies depending on the position of the distance measuring visual field.

Generally, when the distance between the point on the photographic screen and the optical axis of the photographic lens is determined when the aperture of the photographic lens for a camera is open, the optical axis of the exit pupil of the photographic lens is set to this point which is not a paraxial amount. It can be defined by two central circles.

In FIG. 22, reference numerals 73 and 74 denote the exit pupils.
It shows how the above point has been reached. Therefore, the distance measuring light beam in the distance measuring visual field 71 is not vignetted, and whether or not distance measurement is possible depends on whether the distance measuring luminous flux forming the back projection images 74 and 75 is given to each point on the distance measuring visual field. It will be whether you can cross it.

As described above, the exit pupil changes in various states of the taking lens, but in order to appropriately control the distance measuring field of view of the camera according to the attached taking lens, the pupil on the taking lens side should be adjusted. It is necessary to transmit the information of (3) to the camera side and judge whether or not distance measurement is possible for each distance measurement visual field. Table 1 is an example of pupil information of the taking lens for this purpose.

In Table 1, Z1 to Z16 are representative values of the focal length range divided into 16 parts, where Z1 is the wide end and Z16 is the wide end.
Is the tele end. The effective FNo is the effective F number at the darkest range ring position in this focal length range, P
1, R1 is the distance from the planned image-forming plane and its radius of the circle farther from the planned image-forming plane among the two circles that determine the exit pupil at the position 11 mm from the optical axis of the taking lens, P,
2 and R2 are the distance from the planned image plane and the radius of the other circle.

As described above, the microcomputer 355 recognizes the focal length range via the encoders 359a to 359e in the taking lens 2. The ROM in the microcomputer stores the pupil information of Table 1 as a function of the focal length, and the pupil information according to the current focal length is transmitted to the camera body 1. However, since the pupil information is not determined only by the focal length, the pupil information defined here is for the virtual position of the outermost ranging field in each of the divided focal length ranges.

Moreover, it is a value at the distance ring position where the effective F number is the largest in the entire distance range. In fact
For setting the distance measuring visual field position, it is practically sufficient to set the distance measuring visual field position from the optical axis to about 11 mm. Further, in a general photographing lens, the effective F number becomes maximum when the distance ring position is the closest distance.

By having the pupil information in this manner, the effective F number becomes dark as a result of the driving of the taking lens according to the distance measurement result, and distance measurement becomes impossible at this distance ring position. Can be prevented. Also,
If pupil information is defined for the outermost distance measurement field, the actual exit pupil will have a shape including the pupil based on the pupil information for the inner points. It is impossible to determine that there is no vignetting, at least in the case where the vignetting of the light beam is actually determined.

As will be described later, in the sequence of the camera, this pupil information is repeatedly transmitted from the taking lens 3 to the camera body 1 and is used for determining whether or not each distance measuring field of view can be measured and for displaying the distance measuring field of view. The configuration of the focus detection device is not limited to the above-mentioned one, and may have another configuration.

Next, the visual axis detection device according to the present embodiment will be described. The line-of-sight detection device of the present embodiment detects the line-of-sight of the eyeball of the photographer, determines which region in the viewfinder field the photographer is observing, and obtains information obtained at this time, for example, automatic focus detection or photometry. Is used in.

23 to 26 are explanatory views related to the visual axis detection device. FIG. 23 shows an expanded optical path. Figure 2
In FIGS. 3 to 26, 213 is a light source such as a light emitting diode (LED) that emits infrared light that is insensitive to the observer, and is arranged on the focal plane of the light projecting lens (condensing lens) 211.

The infrared light emitted from the light source 213 becomes parallel light by the action of the light projecting lens 211 and the eyepiece lens 215, and illuminates the cornea 221 of the eyeball E1. At this time, the cornea 22
A corneal reflection image (virtual image) d due to a part of the infrared light reflected on the surface of 1 is generated in the vicinity of the iris 223, is condensed by the light projecting lens 211, passes through the half mirror 212, and is on the photoelectric element array 214. The image is re-imaged at the position d '.

The light fluxes from the ends a and b of the iris 223 are transmitted through the light projecting lens 211 and the half mirror 212 to the positions a ′ and b ′ on the photoelectric element array 214 to form images of the ends a and b. Image. When the rotation angle θ, which is the angle formed by the optical axis a of the eyeball with respect to the optical axis of the projection lens 211 (optical axis a), is small, the Z coordinates of the ends a and b of the iris 223 are Za and Zb. The coordinate Zc of the center position c of 223 is expressed as Zc≈ (Za + Zb) / 2.

Further, the Z coordinate Zd of the corneal reflection image d and the cornea 2
Since the Z coordinate Zo of the curvature center O of 21 coincides with the Z coordinate of the corneal reflection image generation position d, Zd, and the distance from the curvature center O of the cornea 221 to the center C of the iris 223 is L _OC ,
The rotation angle θ, which is the angle formed by the optical axis A of the eyeball and the optical axis A, substantially satisfies the relational expression of L _OC * sin θ≈Zc−Zd (1).

For this reason, the position of each singular point (corneal reflection image d and the end portions a and b of the iris) projected on the surface of the photoelectric element array 214 is detected by the calculating means 214b to detect the optical axis of the eyeball. It is possible to obtain the rotation angle θ of, the so-called line-of-sight direction. At this time, equation (1) is

[0084]

[Equation 1] Can be rewritten as However, β is a magnification determined by the position of the eyeball with respect to the light projecting lens 211.

That is, the magnification is determined by the distance L1 between the corneal reflection image generation position and the light projecting lens 211 and the distance LO between the light projecting lens 211 and the photoelectric element array 214.

Here, the principle of line-of-sight detection using the reflection image on the cornea, that is, the so-called Purkinje's first image is shown, but it is known that four images are formed from the structure of the human eye.
However, the intensity is extremely low except for the Purkinje first image, which does not hinder the detection of the Purkinje first image.

Next, the actual operation of the visual axis detection system based on the above principle will be described.

A simple structure using a one-dimensional photoelectric element array is shown below. FIG. 24 is for explaining the method, and as a result of neglecting the vertical detection capability, the photoelectric element 214 having a vertically long shape as shown in FIG.
Since a is arranged, it is almost insensitive to the vertical translation or rotation of the eyeball. However, a similar effect can be obtained by adhering a cylindrical lens in front of the row of photoelectric elements.

In FIG. 25, when the first image 262 of Purkinje shining in the pupil 261 and the pupil 261 are received by the one-dimensional photoelectric element array 214a (photoelectric converter 214).
A photoelectric output such as High output values on both sides represent white eyes. In the dark pupil portion, signals 265 corresponding to the Purkinje first images are obtained.

The pupil center is obtained from the position information of the edge portions 267 and 268. In the simplest case, the pixel number that produces an output near the half value of the average of the iris portion 281 at the edge portion is i
The position coordinates of the center of the pupil, which are ₁ and i ₂ , are given by i ₀ = (i ₁ + i ₂ ) / 2.

The position of the Purkinje first image is obtained from the maximum peak that appears locally in the dark part of the pupil.
From the relative positional relationship between this position and the center of the pupil, it is possible to know the direction of the line of sight according to the state of rotation of the eyeball.
282 and 283 are upper and lower eyelids.

From the output signals of the above-mentioned line-of-sight detecting device, when selecting the range-finding field of the focus detecting device, the one that is closest to the line-of-sight position obtained as described above is selected from the range-finding fields that can be measured. It may be configured as follows. Note that the line-of-sight detection device is not limited to the above configuration, and another configuration can be adopted.

Next, the display device according to this embodiment will be described. The display device in this embodiment includes the external display device using the liquid crystal display DSP shown in FIG. 13 and the in-finder display device. FIG. 14 is an enlarged explanatory diagram of the liquid crystal display DSP. When the shutter speed priority mode is selected by the mode selection member 7, Tv, two arrows, 100, and 100 in the display shown in FIG.
0, 30 ", a 4-digit segment for displaying shutter speed, and one position selected from the distance measuring visual field position displays 6a to 6e are driven.

On the other hand, when the aperture value priority mode is selected, Av, two arrows, and 3 in the display shown in FIG.
2, 1.4, a 4-digit segment for displaying the aperture value, and one selected position of the distance measuring visual field position display elements 6a to 6e are driven.

When the distance measuring field fixing mode button 8 is pressed, the distance measuring field fixing mode is set, and Tv or Av, the 4-digit segment, and the distance measuring field position display elements 6a to 6a.
One of the points 6e selected by the setting dial 5 and the arrow 6f are driven.

Next, the display in the finder is shown in FIG.
Will be explained. FIG. 15 is an explanatory diagram of the distance measuring field frame displayed in the field of view of the finder by the display element (display unit) 25 and the automatic exposure mode display. Reference numeral 20 is a finder field, 21a to 21e are distance measuring field frames, and 28 and 29 are Tv display indicating the shutter speed priority mode and Av display indicating the aperture priority mode, respectively.

As will be described later, the distance measuring visual field frames 21a to 21
The color e is selectively changed by the illumination light from the LED. Further, according to the actual setting state of the cameras 28 and 29, only one of them is in the display state. Further, when the distance measuring field fixing mode button 8 is pressed, Tv or Av,
One of the distance measuring field frames 21a to 21e selected by the setting dial 5 is driven.

16 to 18 are explanatory views for specifically explaining the principle of the superimposed display. Figure 1
6 is a perspective view of the main part of the display device in the finder. 14a to 14e in FIG. 16 are L shown in FIG.
A package for an illumination LED (not shown) including the ED 14c is configured to illuminate each of the ranging field frames 21a to 21e.

As shown in detail in FIG. 17, the display element 25 is provided with a display section 25 made of a phase type diffraction grating at a position corresponding to the distance measuring field. FIG. 17 shows the grating portion in an enlarged manner for facilitating the description of the structure of the diffraction grating, but in reality, the grating pitch is several μm and the thickness of the display element is about 1 mm.

In FIG. 17, 104 is a transparent substrate, and 102 is
Is a diffraction grating configured in the direction perpendicular to the paper surface of FIG.
Is a variable refractive index material, for example, liquid crystal, 103 is a transparent electrode, 105 is incident light having an arbitrary polarization component, 10
Reference numerals 6 and 106 ′ are polarization components orthogonal to each other in the incident light 105, 106 is a component perpendicular to the paper surface, and 106 ′ is a component parallel to the paper surface.

Diffraction grating 102 is controlled by control means (not shown).
By controlling the tilt angle of the liquid crystal 101 by applying an electric field to the liquid crystal 101 filled in the concave portion of the diffraction grating 102 via the transparent electrodes 103 provided opposite to each other,
Light modulation is performed by causing a desired diffraction effect on the incident light 105.

In a static state in which an electric field is not applied to the liquid crystal 101, as shown in the same figure, the liquid crystal 101 is aligned in the recess 102a of the diffraction grating 102 in the grating direction, that is, in the direction perpendicular to the plane of the drawing. It is assumed that the state is maintained. When the incident light 105 is incident on the display element in the static state, the deflection component 10 of the incident light 105
6, 106 ′, the deflection component 106 ′ orthogonal to the alignment direction of the liquid crystal 101 feels the ordinary refractive index no of the liquid crystal 101, and the deflection component 106 parallel to the alignment direction of the liquid crystal 101 is the extraordinary refractive index ne of the liquid crystal 101. Feel

Here, assuming that the refractive index of the substance forming the diffraction grating 102 is ng, the wavelength of the incident light 105 is λ, and the thickness of the diffraction grating 102 is T, the incident light 1 is 1 in the case of a rectangular diffraction grating.
The diffraction efficiency ηo of the zero-order transmitted diffracted light with respect to each of the deflection components 106 and 106 ′ of No. 05 is approximately represented by the following expression (3).

[0104]

[Equation 2] Where Δn is the refractive index ng of the diffraction grating 102 and the liquid crystal 10
The refractive index difference with the refractive index ne or no of 1 is shown.
= | Ne-ng |, for the deflection component 106 ', Δn
= | Ng-no |.

Therefore, from the equation (3), when Δn = 0, that is, when ne = ng or no = ng, the diffraction efficiency ηo of the zero-order transmitted diffracted light becomes ηo = 1, and ΔnT = (1/2 + m ) Λ (m = 0, 1, 2, 3, ...), the diffraction efficiency ηo is ηo = 0.

Next, when an electric field is applied to the liquid crystal 101 through the transparent electrodes 103 and 103 ', the alignment direction (optical axis direction) of the liquid crystal 101 gradually changes. Along with this, the ordinary refractive index no of the liquid crystal 101 is always felt regardless of whether or not the electric field is applied to the deflection component 106 'of the incident light 105.

On the other hand, the deflection component 106 has an extraordinary refractive index ne and an ordinary refractive index no of the liquid crystal 101 according to the amount of applied electric field.
And feel the combined refractive index nθ combined at a predetermined ratio.
Here, the composite refractive index nθ changes with the change of the alignment direction of the liquid crystal 101.

When the amount of applied electric field is further increased, the liquid crystal 101
Are aligned vertically to the substrate 104 (transparent electrode 103), and are in a homeotropic alignment state. At this time, the incident light 105
The polarization components 106 and 106 'of both sense the ordinary refractive index no of the liquid crystal 101 and saturate. In this state, the incident light 105 is diffracted according to the equation (3), that is, light is modulated.

Based on such a principle, a non-display state (first operation mode) and a display state (second operation mode)
Can be switched.

That is, in the non-display state, the display element 25 is regarded as a transparent substrate having a uniform refractive index, and the subject image formed by the taking lens formed on the focus surface passes through the viewfinder without being modulated. System pentaprism 11,
The image is directly formed on the retina of the eye for observation via the eyepiece lens 12. In the display state, a part of the light from the photographing lens that enters the display element 25 is diffracted by the diffraction grating portion that is the display pattern. Of the diffracted light, a component having a large diffraction angle is blown out of the aperture of the eyepiece lens 215, so that part of the subject light is visually recognized as being dimmed, and the display overlaps with the subject image.

Further, the packages 14a to 14a shown in FIG.
When an illumination LED (not shown) held by 14e is caused to emit light, the light flux passes through the light projecting lens 13 as shown in FIG. 12, is reflected by the movable half mirror 9, and is focused on the focus glass 10.
Is deflected to reach the display body 25. At this time, by the action of the Fresnel lens 13a of the light projecting lens 13, one LED is emitted to illuminate one display section.

FIGS. 18A and 18B are detailed views of the portion A shown by the broken line in FIG.
14e shows the optical path of the illumination light from the LED held by 14e. In FIG. 18A, 22 and 23 are LEs.
With the illumination light from D3, the movable half mirror 9 causes the display 2
It is obliquely incident toward 5. The figure shows a case where the display unit 10c is in a display state by applying an electric field, and the light ray 22 incident on the diffraction grating 30 (FIG. 18B) is diffracted here. A part of this diffracted light travels upward, while the light ray 23 directly travels toward the ineffective portion of the pentaprism 11.

Therefore, the pentaprism 11 and the eyepiece 1
Observing the display portion 10c through 2, if the display portion is originally in the display state, the color changes to the emission color of the LED, and in the non-display state, the illumination light from the LED is bent toward the eyepiece lens. It is not visible because it does not exist.

As described above, by combining the application of the electric field by the transparent electrode 103 and the irradiation of the illumination light by the LED, there are three operating states of the non-display state, the display state and the color change display state for each distance measuring field frame. Can be controlled about.

FIG. 18B is a diagram for explaining the state of diffraction of the illumination light in more detail, and shows the behavior of light rays in the display element 25. In the figure, θ0 is the incident angle of the light beam on the display element 25, θ3 is the outgoing angle from the display element, θ1 is the incident angle on the diffraction grating, and θ2 is the outgoing angle from the diffraction grating. First, inside the display element, the m-th order diffracted light satisfies the following equation.

Sin θ2-sin θ1 = mλ / (dn) (4) m: integer λ: wavelength of illumination light in air n: refractive index of transparent substrate 104 θ0, θ1 and θ2, θ3 The relationship is sin θ0 = nsin θ1 (5) sin θ2 = nsin θ3 (6), and by substituting equations (5) and (6) into equation (4), θ0-sin θ3 = mλ / d (7)

In the single-lens reflex camera as shown in FIG. 12, θ0 is about 30 degrees and the wavelength λ of the LED is 65 degrees.
If 0 nm, θ3 = 0, and m = 1, then d = 1.3 nm. Therefore, if the pitch of the diffraction grating is set to this value, the first-order diffracted light is emitted in the direction of the eyepiece lens 215, and the distance measuring frame in the display state is visible in red.

Next, the operation of the camera of this embodiment will be described with reference to FIGS. FIG. 27 is a flow chart showing the flow of the entire program stored in the microcomputer 310.

When the execution of the program is started by operating the switch 319, the switch 3 which is turned on by the first stroke of the release button 4 in step (002).
21 (SW1) is detected, and when the switch 321 is OFF, the process returns to step (002) and the detection of the release button 4 is repeated.

On the other hand, when the switch 321 is turned on, the process proceeds to step (003). Step (0
Reference numeral 03) is a "distance measuring field display" subroutine, which displays a distance measuring field frame capable of distance measurement by the liquid crystal display DSP, the display element 25, and the LEDs 1 to 5 and displays the selected distance measuring field.

The following step (004) is an "exposure / film control" subroutine, in which a series of camera operation controls such as photometric calculation processing, exposure control, shutter charge after exposure, film winding and the like are performed. The "exposure / film control" subroutine is not directly related to the present invention, so a detailed description thereof will be omitted, but the outline of the function of this subroutine is as follows.

While the switch 321 is ON, this "exposure / film control" subroutine is executed, and photometry and exposure control calculation / display are performed each time. When the switch 322 (SW2) is turned on by the second stroke of the release button 4, the release operation is started by the interrupt processing function of the microcomputer 310, and the aperture or the aperture is calculated based on the exposure amount obtained by the exposure control calculation. The shutter time is controlled, and after the exposure is completed, the shutter charge and the film feeding operation are performed to complete the photographing of one frame of film.

Step (005) is "line of sight / AF control"
In the subroutine, the line-of-sight detection device detects the line-of-sight of the photographer's eye, the focus detection in the distance-measuring field selected according to the line-of-sight position, and the focus control of the photographing lens. When this series of processing is completed, the process returns to step (002) and S
W1 is detected.

Next, the "distance measuring field of view display" subroutine will be described with reference to FIG. In the "distance measurement visual field display", first, in step (102), pupil information is communicated.

Specifically, from the data (Table 1) stored in the ROM incorporated in the microcomputer 355 of the taking lens 2, the P corresponding to the current zoom position is selected.
1, R1, P2, R2 are sent to the microcomputer 310 in the camera body 1 and stored in the RAM.

In the following step (103), P1, R
By comparing the values of 1, P2 and R2 with the information on the distance measuring light flux unique to the focus detection device, the vignetting of the distance measuring light flux is checked for each distance measuring visual field, and whether or not distance measurement is possible is determined based on the presence or absence of vignetting.

In step (104), the display element 25 is driven so that the distance measuring frame is displayed only in the distance measuring field of view according to the judgment result in the previous step. However, when the distance measuring field fixing mode button 8 is operated, the distance measuring frame of one selected distance measuring field is driven.

At step (105), the subroutine is returned. Since this subroutine is repeatedly called in the sequence of the entire camera shown in FIG. 27, the latest zoom position is always checked and the usable distance measuring field of view is displayed in substantially real time.

The "line-of-sight / AF control" subroutine will be described with reference to FIG. In "line-of-sight / AF control", first, in step (202), it is checked whether or not the lens is being driven for focus control. If the lens is being driven here, it means that the lens driving by the "line-of-sight / AF control" subroutine of the previous time has not been completed yet, and therefore the process proceeds to step (209) and the subroutine is immediately returned. If the lens is not being driven, the process proceeds to step (203). In step (203), the visual axis of the photographer's eye is detected by the visual axis detection device.

In the following step (204), a distance measuring field for focusing control is set based on the result of the sight line detection.
As shown in the explanation of the "distance measuring field display" subroutine,
A range-finding frame corresponding to the range-finding field capable of measuring a distance is displayed in the viewfinder field, and the range-finding field closest to the line-of-sight detection result is selected. Even in the fixed distance measuring field mode, this routine is passed in order to allow the focus detection operation only when the photographer is looking through the viewfinder. It can be an action.

In step (205), the object in the distance measuring field set in the previous step (204) is
Focus detection is performed, and in step (206), focusing /
Determine out of focus.

If it is determined that the lens is out of focus, the process proceeds to step (208) to instruct the photographing lens to drive the lens based on the defocus amount. On the other hand, if it is determined that the lens is in focus, the step is performed. At (207), focus display is performed.

This focusing display is performed by the LED shown in FIG.
This is performed by turning on one of 1 to 5 corresponding to the set distance measuring field and changing the color of the distance measuring frame of the display element 25. Also, this lighting time is several tens of ms to several tens.
Practically preferable is about 0 ms.

Finally, of the operations of the camera according to the above-described flowchart, display in the viewfinder will be described with reference to FIGS. 30 (A), (B), 31 (A), and (B).

FIG. 30A shows a case where a bright photographic lens having a small F number is mounted, or a comparatively F lens is used.
Even if the number is large and the shooting lens is dark, there is an exit pupil at a position where the distance measuring light beam is not vignetted, and if all the distance measuring fields of the focus detection device can measure the distance, Shows the viewfinder display, viewfinder field 2
In 0, Tv display indicating the shutter speed priority mode and the distance measuring frames 21a to 21e are shown. In the drawing, the display state of the distance measuring frame is shown by a double line, but in reality, the subject light is dimmed only in the display portion due to the diffractive action of the display element 25, and it appears almost black.

On the other hand, in FIG. 30B, it is detected that the line of sight of the photographer is in the vicinity of the distance measuring visual field 21b, and the photographing lens is detected based on the focus detection result of the distance measuring visual field corresponding to this. As a result of being driven, a focus display when the focus state is reached is displayed, and a color change display of the distance measuring frame 21b is displayed.

In the drawing, the distance measuring frame is shown by being painted over, but in reality, the distance measuring frame looks colored in the light emission color of the LED.

FIGS. 31 (A) and 31 (B) show the case where the distance measuring light beam is apt to be vignetted even when a dark photographic lens having a large F number is attached, or even when a photographic lens having a relatively small F number is bright. The viewfinder display is shown when there is an exit pupil and the distance measuring field outside the focus detection device cannot measure the distance. In FIG. 31A showing the state before focusing, only the three distance measuring frames at the center are displayed, and the photographer can know the operating condition of the distance measuring field while looking through the viewfinder.

In FIG. 31B, similar to FIG. 30B, the distance measuring frame corresponding to the focused distance measuring visual field is changed to the LED emission color, and the photographer is informed that it is in focus. Inform.

[0140]

[Table 1] As described above, according to the present embodiment, by controlling the diffraction state of the phase type diffraction grating, the light flux from the photographing lens can be made non-incident to the finder system, and the light flux from the illumination means can be incident to the finder system. And the second operation mode in which the light flux from the photographing lens is incident on the finder system and the light flux from the illumination means is not incident on the finder system. effective.

(2-a) A superimpose display capable of display / non-display switching which can be constructed while keeping the finder image bright, and also has a non-display state / display state /
It has become possible to switch between the three color change display states.

(2-B) In particular, since the color change display state is an active display, the visibility is good even for a dark subject, and it is most suitable for the display essential for the photographing operation.

(2-C) If this display device is used for displaying a distance measuring field for focus detection, an unusable distance measuring field is not displayed depending on the state of the taking lens, and a usable distance measuring field is displayed. The focus detection operation can be extremely clearly recognized by the photographer by displaying the focus detection frame and displaying the focus display in the color change display.

(2-d) Further, in the focus detecting device for setting the distance measuring visual field based on the output of the visual axis detecting device,
By making the distance-measuring field incapable of distance measurement invisible and displaying only the distance-measuring field in which distance measurement is possible, the photographer is made aware of the operating state of the focus detection device, and distance measurement that can measure the line of sight. It can be oriented in the direction of the field of view.

[0145]

As described above, according to the present invention, (3-a) an appropriately set optical means is provided between a light source for illuminating a plurality of display portions and a light projecting lens, and the optical means is used. By efficiently illuminating the plurality of display portions, it is possible to achieve a display device which is bright and enables observation with good visibility.

(3-b) By forming a complicated display section using a phase type diffraction grating and appropriately setting the configuration of the illumination means for illuminating the plurality of display sections, the finder image can be kept bright. It is possible to achieve a display device in which one display unit can be selected from a plurality of display units and satisfactorily observed.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part of a first embodiment when the present invention is applied to a single-lens reflex camera.

FIG. 2 is an optical path diagram in which an optical path of a part of FIG. 1 is expanded.

FIG. 3 is a perspective view of a mask used in an illumination optical system for superimpose display.

FIG. 4 is an enlarged view of optical members used in the illumination optical system for superimpose display.

FIG. 5 is a plan view of a main part of a conventional single-lens reflex camera.

FIG. 6 is a sectional view of a conventional single-lens reflex autofocus camera having a display device in a finder.

FIG. 7 is an explanatory diagram showing a display in a viewfinder of a single-lens reflex autofocus camera.

FIG. 8 is a perspective view of a conventional viewfinder display device.

FIG. 9 is a perspective view of the focus glass and an explanatory view of the principle of the superimposed display.

FIG. 10 is a schematic view of the essential portions of Embodiment 2 when the present invention is applied to a single-lens reflex camera.

FIG. 11 is a schematic view of the essential portions of Embodiment 2 when the present invention is applied to a single-lens reflex camera.

FIG. 12 is a cross-sectional view of the essential parts of Embodiment 2 when the present invention is applied to a single-lens reflex camera.

FIG. 13 is a plan view of the essential parts of Embodiment 2 when the present invention is applied to a single-lens reflex camera.

14 is an explanatory diagram showing all the segments that can be displayed in the external display device of the single-lens reflex camera in FIG. 11. FIG.

15 is an explanatory diagram showing all the segments that can be displayed in the viewfinder of the single-lens reflex camera in FIG. 11. FIG.

16 is a perspective view of a display device in a viewfinder of the single-lens reflex camera in FIG. 11. FIG.

FIG. 17 is an explanatory view of the principle of the display element.

FIG. 18 is an explanatory diagram of the principle of active color change display.

FIG. 19 is a perspective view of a focus detection device.

FIG. 20 is a sectional view of the focus detection device.

FIG. 21 is a plan view showing the relationship between a focus detection photoelectric conversion element and a field mask image.

FIG. 22 is a perspective view showing the relationship between the distance measuring light flux of the focus detection device and the photographing light flux of the photographing lens.

FIG. 23 is an explanatory view of the principle of the eye gaze detection device.

FIG. 24 is an explanatory diagram showing a relationship between a line-of-sight detection photoelectric detection device and a pupil image projected thereon.

FIG. 25 is a front view of a photographer's eye illuminated by an LED light source.

26 is an explanatory diagram showing photoelectric conversion output when the photographer's eyes are photoelectrically converted by the photoelectric conversion element in FIG. 24.

FIG. 27 is a flowchart showing the sequence of the entire camera.

FIG. 28 is a flowchart of a “distance measuring field of view display” subroutine.

FIG. 29 is a flowchart of a "line-of-sight / distance-measuring visual field display" subroutine.

FIG. 30 is a view explaining the operation of the finder display.

FIG. 31 is an operation explanatory view of the finder display.

[Explanation of symbols]

 1 Camera Main Body 2 Lens Barrel 3 Photographing Lens 4 Release Button 5 Setting Dial 6 LED 7 Mode Selection Member 8 Distance Measurement Field Selection Mode Button 9 Movable Half Mirror 10 Focus Glass 11 Penta Prism 12 Eyepiece 13 Projection Lens 16 Focus Detection Device 25 display section 32 optical member

Claims (3)

[Claims] 1. A plurality of display portions having a light deflecting property are arranged in the vicinity of a planned image forming surface where an object image is formed by an objective lens, and light beams from a plurality of light sources are passed through an optical member and a light projecting lens. When selectively illuminating a predetermined display unit of the plurality of display units and observing the illuminated display unit and the object image, the optical member is configured to display two adjacent display units of the plurality of display units. A display device, wherein one of the two optical paths for illumination guides the light flux from the light source to the light projecting lens side through reflection. 2. A plurality of display sections using a phase type diffraction grating are provided near an expected image formation surface where an object image is formed by an objective lens, and the plurality of display sections are displayed by light beams from an illumination means having a plurality of light sources. When a predetermined display section of the display section is selectively illuminated and diffracted light generated by the diffraction grating of the illuminated display section is guided to a finder system, the display section and the object image are controlled when observed. Means for controlling the diffraction state of the diffraction grating so that the light flux from the taking lens is not incident on the finder system and the light flux from the illuminating means is incident on the finder system; A display device, wherein a light flux from a lens is incident on the finder system, and a second operation mode in which the light flux from the illumination means is not incident on the finder system is switched. 3. The diffraction grating is a relief type diffraction grating provided between two substrates, and the control means changes the refractive index of a refractive index variable substance filled between the substrates to thereby perform the diffraction. The display device according to claim 2, wherein the diffraction state of the grating is controlled.